Certified Rhythm Analysis Technician (CRAT) Practice Exam

Question: 1 / 400

What does a deflection of the tracing upward or downward by one large box from the baseline on an ECG graph paper represent?

0.25 millivolt

0.5 millivolt

In ECG graph paper, the vertical axis represents voltage, and each large box typically corresponds to a specific voltage value in millivolts. A deflection of the tracing upward or downward by one large box from the baseline indicates a change in voltage of 0.5 millivolts. This measurement is derived from the standard calibration of ECG machines, where each large box represents 5 small boxes vertically and each small box corresponds to 0.1 millivolt. Therefore, 5 small boxes equal 0.5 millivolts when summed together. This means that a deflection by one large box signifies a voltage change of 0.5 millivolts. Understanding this calibration is crucial for accurately interpreting ECG readings and assessing cardiac health.

Get further explanation with Examzify DeepDiveBeta

1.0 millivolt

1.0 volt

Next Question

Report this question

Subscribe

Get the latest from Examzify

You can unsubscribe at any time. Read our privacy policy